Using Variables within SSIS Sybase query

Hi,

I have a query in SSIS which links to Sybase.  A previous employee wrote the query which looks like: -

SELECT Timestamp, AgentGivenName, AgentLogin, CallsOffered, CallsAnswered
FROM blue.dbo.iAgentPerformanceStat
WHERE AgentGivenName = 'Grapevine'
AND Timestamp > ''

Basically he has inserted a variable value where the two single quotes are at the end.  How has he done this?  The only options I see when viewing the code are a 'Build Query' & 'Browse' buttons.  I have tried going into advanced editor and I still can't find any parameter options.

I can see the variable he used on the left but how did he link it to replace the query?